Lead plays an interesting role in the history of workplace safety. The naturally occurring heavy metal was one of the first metals used by early workers. So it may come as no surprise that the substance was the cause of the first recorded occupational health issue, when a metalworker developed “lead colic” in the 4th Century BCE.
In the centuries that followed, lead was extensively use in human commerce, whether by itself, or combined with other substances to form alloys or compounds. As society learned more about the health dangers associated with lead, some uses — primarily its role as an additive to housepaint and gasoline — were banned, but industrial applications continue.
How humans encounter lead
Workers may encounter lead in many settings, including the production, use, maintenance, recycling, and disposal of materials containing the metal. Besides manufacturing, lead may still be found in construction, transportation, and remediation, among other industries.
Typically, workers become exposed to lead when they inhale or ingest lead-containing dust or fumes. For example, construction workers may be exposed to lead when demolishing or renovating older structures that were painted with lead pigments. Plumbers may handle lead pipes and fittings or use solder that emits lead fumes. Other workers may encounter lead in everything from the linings of storage tanks, to rechargeable vehicle batteries, to bullets.
Beyond inhaling lead dust or fumes, workers may also be exposed by eating, biting nails, or smoking if their hands have been exposed to lead and they have not been properly washed. Workers can also track lead dust on their shoes and unwittingly bring it into their homes, where other family members may be exposed.
Lead’s many health dangers
Unlike many toxic compounds, lead cannot easily enter the body through skin. Most of the time, it passes into the blood through the lungs. Once lead is present in blood, it can travel throughout the body, where it may accumulate in the bones and harm organs. Over time, that harm can lead to anemia, kidney disease, infertility, gastrointestinal problems, and neurological effects. Lead exposure is particularly dangerous for women who are (or become) pregnant, because lead is highly toxic to the fetus.
Exposure to lead may result in any number of symptoms that can be mistakenly attributed to other causes, among them:
- memory/concentration difficulties,
- stomach pain,
- weight loss, and
Protecting against lead exposure
Because lead dust and fumes may not be obvious, and because the potential for health defects increases as lead accumulates in the body, it’s important for employers and workers to take steps to limit the amount of exposure.
OSHA requires protection from inorganic lead exposure, with air testing and standards calling for a permissible exposure limit (PEL) of 50 micrograms per cubic meter over an eight-hour time-weighted-average and an action level of 30 micrograms per cubic meter. Compliance steps include blood tests for workers who have been exposed, involving the possibility of medical surveillance and biological monitoring.
As with most safety hazards, finding ways to reduce the hazard is preferred. For example, employers can choose lead-free or reduced-lead alternatives in place of products that contain lead. They can increase ventilation in areas where lead dust or fumes are present and require appropriate personal protective equipment (PPE) for the tasks and environment.
Workers must follow safety strategies when working with or around lead, including wearing the specified PPE and following hygiene procedures such as washing hands and scrubbing fingernails before drinking, eating, or smoking. Workers should also take steps to avoid contaminating family members by washing and changing before going home and not washing PPE at home. Finally, keeping work areas neat and clean can also reduce exposure to lead.